dormer extensions?

[legepe]

Hi all,

I am trying to understand what is required in the structural aspects of building dormer extensions - what materials, easiest and most cost effective way... if poss..!
I have made a building control application but still havent had first visit from them.
I have attached here 2 photos and a PDF plan showing the current layout and my proposed layout. The red lines on the plans are the current supporting beams but the ones nearest to exterior walls will obviously need to be removed.
How can i support the roof/floor.? what will the building control require?
Can anyone please advise
Thanks a lot
legepe

cawood milica.pdf

[MikeSharp01]

Structuraly you need to take the new end load of those beams down to the ground somehow as the ceiling joists for downstairs run the wrong way you will have to be creative by spanning the downstairs walls to front to back and double (at least) up the ceiling joists to provide that support. However you ho you need a structural engineer to sign off on it as BC won't accept it otherwise.

[PeterW]

IIs that a detached property and the full width of the roof ..?

 

If so, I’d be inclined to take the whole roof off and start again if you want to put front and back dormers ..? Even with just a back dormer it’s a lot of work, any of the walls below structural ..?? I doubt you can get any decent levels of insulation in those dormer cheeks as it stands. 

 

Could be simpler to put a steel at floor level and build up off that if you have space to get it in as it’s going to be a min 254 I would expect.